<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <link rel="stylesheet" href="./css/inputnumber.css" />
  <link rel="stylesheet" href="./css/index.css" />
  <title>购物车</title>
</head>

<body>
  <div class="app-container" id="app">
    <!-- 顶部banner -->
    <div class="banner-box"><img src="http://autumnfish.cn/static/fruit.jpg" alt="" /></div>
    <!-- 面包屑 -->
    <div class="breadcrumb">
      <span>🏠</span>
      /
      <span>购物车</span>
    </div>
    <!-- 购物车主体 -->
    <div class="main" v-if="fruitList.length>0">
      <div class="table">
        <!-- 头部 -->
        <div class="thead">
          <div class="tr">
            <div class="th">选中</div>
            <div class="th th-pic">图片</div>
            <div class="th">单价</div>
            <div class="th num-th">个数</div>
            <div class="th">小计</div>
            <div class="th">操作</div>
          </div>
        </div>
        <!-- 身体 -->
        <div class="tbody">
          <!-- 1.渲染页面 -->
          <div class="tr active" v-for="e in fruitList" :key="e.id">
            <!-- 1.1双向绑定  -->
            <div class="td"><input type="checkbox" v-model='e.isChecked' /></div>
            <!-- 1.2动态绑定 -->
            <div class="td"><img :src="e.icon" alt="" /></div>
            <div class="td">{{e.price}}</div>
            <div class="td">
              <div class="my-input-number">
                <!-- 3.修改个数 -->
                <button class="decrease" @click="lis(e)"> - </button>
                <span class="my-input__inner">{{e.num}}</span>
                <button class="increase" @click="e.num++"> + </button>
              </div>
            </div>
            <!-- 1.3 此处不用 computed 他只能求一组数据 -->
            <div class="td">{{e.price*e.num}}</div>
            <!-- 2.删除功能 -->
            <div class="td"><button @click="del(e.id)">删除</button></div>
          </div>
        </div>
      </div>
      <!-- 底部 -->
      <div class="bottom">
        <!-- 全选 -->
        <label class="check-all">
          <!-- 4.全选反选 双向绑定 -->
          <input type="checkbox" v-model="bigCek" />
          全选
        </label>
        <div class="right-box">
          <!-- 所有商品总价 -->
          <span class="price-box">总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price">{{add1}}</span></span>
          <!-- 结算按钮 -->
          <button class="pay">结算( {{add2}} )</button>
        </div>
      </div>
    </div>
    <!-- 空车 -->
    <!-- 1.4底部区域默认不显示 没有数据了显示 使用v-if v-else -->
    <div class="empty" v-else>🛒空空如也</div>
  </div>
  <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        // 水果列表
        // 逻辑中断判断使用的内容是本地或这默认
        fruitList: JSON.parse(localStorage.getItem('list')) || [
          {
            id: 1,
            icon: 'http://autumnfish.cn/static/火龙果.png',
            isChecked: true,
            num: 2,
            price: 6,
          },
          {
            id: 2,
            icon: 'http://autumnfish.cn/static/荔枝.png',
            isChecked: false,
            num: 7,
            price: 20,
          },
          {
            id: 3,
            icon: 'http://autumnfish.cn/static/榴莲.png',
            isChecked: false,
            num: 3,
            price: 40,
          },
          {
            id: 4,
            icon: 'http://autumnfish.cn/static/鸭梨.png',
            isChecked: true,
            num: 10,
            price: 3,
          },
          {
            id: 5,
            icon: 'http://autumnfish.cn/static/樱桃.png',
            isChecked: false,
            num: 20,
            price: 34,
          },
        ],
      },
      methods: {
        // 删除功能实现
        del(id) {
          this.fruitList = this.fruitList.filter(e => e.id !== id)
        },
        // --功能实现
        lis(e) {
          if (e.num === 1) {
            return
          }
          e.num--
        }
      },
      computed: {
        // 通过计算来判断反选
        bigCek: {
          get() {
            // 判断所有小选 如果都满足ture bigcek为ture
            return this.fruitList.every(e => e.isChecked)
          },
          set(newVal) {
            // 将bigcek的所有值赋给每个小选
            this.fruitList.forEach(e => {
              e.isChecked = newVal
            })
          }
        },
        // 计算选中的总价
        add1() {
          return this.fruitList.reduce((prev, e) => {
            if (e.isChecked) {
              return prev + e.num * e.price
            } else {
              return prev
            }
          }, 0)
        },
        // 计算总数
        add2() {
          return this.fruitList.reduce((prev, e) => {
            if (e.isChecked) {
              return prev + e.num
            } else {
              return prev
            }
          }, 0)
        }
      },
      watch: {
        // 7.持久化数据到本地
        // 监听fruitList
        fruitList: {
          // 深度监听
          deep: true,
          handler(newVal) {
            // 将数据储存到本地
            localStorage.setItem('list', JSON.stringify(newVal))
          }
        }
      }
    })
  </script>
</body>

</html>